Extreme HTML Optimization: The Future and Conclusion
Extreme HTML Optimization
To get really radical reductions in page size and boost display speed, you've got to literally think outside the box (read table). Using CSS2 positioning (supported by nearly 90% of current browsers), you can achieve the holy grail of separation of presentation from content, and speed up your Web site in the process. CSS2 uses style sheets to position DIVs etc. within your page, and can create table-like displays, without the messy and byte-hungry table skeleton. You can even move up the most important content (what users look for first anyway) to the top of your style sheet, to display it first. See HTML with Style and A List Apart for live examples of table-like layout, without tables.
We're working towards a CSS2 version of the home page, but have yet to make our complex layout work. If you've got a CSS2 solution, let us know, and we'll mention your name in the next update.
Ask your IT department to upgrade your server to HTTP1.1, and you'll see a dramatic improvement in page display speed. HTTP1.1 uses pipelining, and persistent connections to streamline the multiobject page display typical on the Web today. HTTP1.1 is even faster than HTTP1.0 keep-alive. HTTP1.1 can also employ zip compression of the body of your pages (typically a three-fold reduction in page size), for browsers that support this. The Net effect is less packets sent, one TCP connection rather than many (avoiding the slow-start syndrome and overhead), and a dramatic increase in speed. See the W3C's site for more details.
(1) With the average network bandwidth of 5 KBps and the majority of Net users connect and 56 Kbpbs (until at least 2003) that works out to about 34-40 KB/page. (5KBps X 8 seconds = 40KB, but more it realistically a 56 Kbps modem gives about 2.4-3 KBps effective transfer rate which means 3KBps X 10 seconds = 30KB maximum page size. Jakob Nielsen recommends a maximum of 34KB/page, which includes latency). See useit.com for details.
(2) Bailout rate (the percentage of users who don't wait for your page to download) decreases were documented by both Zona research, and Jakob Nielsen for pages that displayed less than 8-10 seconds. Home pages larger than 40-50K had bailout rates of 25-30%, when reduced to less than 34K the bailout rates dropped to 7-10%.
- WebReference Main Page
- Evolution of a Home Page - includes HTML speed tips
- Optimization and Obfuscation Resources
- What Makes a Great Web Site?
- Speed Up Your Site
- Book Summary: Designing Web Usability
- Great Tips from CNET's Designers - Lists speed techniques used at CNET
- useit.com - Jakob Nielsen's Usability Site
- HTML OptimizersFrom Ton's Software
- Remote Communications - Offers free/pay mod_gzip Apache module
- URLs, URLs, URLs! - A List Aparts talks Redirects
- WebSiteOptimization.com - Speed tips and tricks used at WebReference.com, by Andy King.
- Zona Research : The Economic Impacts of Unacceptable Web Site Download Speeds
Revised: Jan. 22, 2003